Efficiently supplying heat to a building is a major concern for many. One industry solution is the use of radiant heating systems. These systems work by laying a pipe network underneath a building's floor. Heated water circulates through the pipes, evenly warming the floor. The heated floor radiates heat to the occupied space. Because the heating element in the room is the mass of floor and objects on the floor, areas closer to the floor will be warmer than those near the ceiling. The heat is retained by the mass in the lower areas of the room where the occupants are instead of allowing it to amass in the farthest heights of the room. Furthermore, the large surface area of the floor ensures horizontal heat uniformity in the room.
As previously mentioned, radiant heating systems use a pipe network to heat a floor. This network is usually achieved by covering a substantial portion of the floor's underside with flexible pipe made of high density polyethylene with an altered molecular structure that prevents the passage of oxygen through it. This type of plastic is often referred to as “PEX,” short for cross-linked polyethylene. PEX is made in different grades each with a different method of oxygen barrier, if any, used during its production. PEX A is preferred in radiant heating systems because it has the most reliable method of resisting the passage of oxygen through its walls. Other pipe materials may consist of rubber, or other types of plastic that attempt to achieve the same objective of allowing heated water to pass through its length in a heating system, and have different methods of resisting the passage of oxygen through its walls. PEX piping has many advantages. It is inexpensive and does not corrode like metal. Further, it may be expanded without fracture, and then returned to its original shape. This allows it to be quickly and reliably joined together using a single pipe-expansion tool, which expands the end of the pipe to accept a barbed type fitting, which it tightly conforms to, sealing water in and air out. Further, it is easily cut and reattached using the same tool in the event that a repair must be made on the system.
A number of tools have been developed to join PEX piping to barbed connectors and these tools work reasonably well. Further, a number of joining systems, utilizing collars and other means for exerting downward pressure on the area of the pipe surrounding the barbs of the fittings, have been developed. These systems have proven to be very quick and assure reliable and leak free joints. Accordingly, it would be desirable to use this type of piping wherever connections need to be made.
Unfortunately, in the cross sections currently used, the PEX piping is substantially flexible when heated to the working temperatures of the system and may not be effectively used in horizontal or vertical runs from the boiler to the flow components and radiant manifold, due to unsightly sags and the mechanical stresses they can cause. Thus, while the use of PEX piping is ideal for the floor, traditional soldered copper and threaded steel piping systems are currently used to join the source of hot water to the various flow components and manifolds to which the PEX pipes are ultimately connected. However, these piping systems have a number of drawbacks that add to the overall cost of installing and maintaining the system.
One problem with traditional piping systems is the time required to design and install them. Typically these piping systems use flanges, threaded fittings, black steel pipe, or sweat fit copper tubing, which is extremely labor intensive to estimate, design, and install. Manufactured steel and copper piping or tubing come in straight runs and fittings for accommodating turns and curves. Each connection of a straight run with a fitting requires either a threaded or a sweat fitted solder connection and a substantial amount of installation labor is involved in making each joint.
In cases where threaded connections are to be made, the pipe must be cut to the appropriate length, and then the threads must be cut on the end of the pipe using a pipe threading die. Next, the threads must be dressed, cleaned and coated with a sealing compound, or a TEFLON®, or other synthetic resinous fluorine tape, to prevent leaks. Finally, the connector must be screwed to the pipe end with sufficient thread contact to prevent leaks.
In the case of sweat fit solder joints, the labor is comparable in that the tubing must be cut to the proper length, the end of the tubing and the fitting must be dressed and fluxed and the joint must be heated to the proper temperature with a torch to effect a satisfactory solder joint. Once joined, the solder connection must then be cleaned of any residual flux that, if left un-cleaned, may corrode the joint once exposed to moisture.
In the case of flanged connections, such as those found on, virtually, all conventional circulators, the attachment is just as labor intensive. Circulator flanges are typically elliptical in shape and do not readily accommodate a standard pipe wrench or other tightening device. In addition, when the elliptical ends of the flange have turned within the one-hundred and eighty degrees tightening arc, the wrench must be readjusted, necessitating many fatiguing and time consuming iterations to complete the task. Moreover, as the size of a pipe wrench increases, the length of the handle increases proportionally. As pipe flanges must often be attached to a circulator that is extremely close to a wall, other pipes, or even worse, a corner, the use of a long handled pipe wrench or a pry-bar and long stove bolts to attach the flange to the pipe makes this job a tiring and time consuming one. Finally, once attached to the pipe, gaskets must be installed between the flanges and bolts secured to each flange to make the connections watertight. The inventor's pipe flange and sweat flange, described and claimed in co-pending U.S. patent application Ser. No. 09/179,584, and U.S. Pat. No. 6,283,157, respectively, ease this installation job somewhat. However, each still requires many of the same steps required for installing threaded or sweat copper connections, and each still requires the use of gaskets and bolts to secure the flanges to one another.
Another reason for the increase in installation cost is the fact that most systems are customized for the particular location in which they are to be installed. This requires that a variety of parts, having a variety of different connections, be used to piece the system together. Consequently, trained professionals who have the tools and the know-how to properly assemble such customized systems are required to install current systems.
Finally, the replacement of failed components in current systems requires that pipes be cut, rusted bolts be removed, worn gaskets be replaced, etc. This, again, increases the complexity of the work to be performed and mandates that trained professionals undertake any repair work on current systems.
Therefore, there is a need for a heated water delivery system that utilizes PEX piping between the boiler, flow components and the manifold, that is easily installed using art-recognized tools, that is substantially rigid when installed, and that may be prepackaged in kit form for further ease of installation.